The 14-day letter (WIK letter) in 2026.

The 14-day letter is the mandatory final demand letter to a private customer before you are allowed to charge legal collection fees. This letter is stipulated in the Collection Costs Act and offers consumers additional protection.

The idea behind the law is simple: a consumer should always be given the chance to pay the principal amount first, without additional fees or penalties. Only after the 14-day period from the letter has expired may you charge collection fees.

When is the 14-day letter mandatory or wise?

• Individuals (B2C): Always required. Without a valid 14-day letter, the court will often reject your collection charges.
• Zzp'ers: In some cases, zzp'ers are protected just like consumers. Don't want to be at risk? Send a 14-day letter to zzp'ers, too.
• Businesses (B2B): Not required by law, but a strong and clear final step in your collection process.

At Credifin, we make sure your 14-day letter is legally sound, clearly worded and fully compliant for 2026.

The timing of your 14-day letter is important. If you send the letter too early or with the wrong deadline, you may lose your right to collection fees.

You send the 14-day letter in these situations:

• Your client is an individual or self-employed person.
• The invoice payment period has expired.
• You may have already sent one or more payment reminders or reminders.

From then on, you take the formal step: the 14-day letter. In that letter, you give your customer one clear last chance to pay the principal amount, without additional charges.

Are you sending the letter by mail? Then also keep in mind the delivery time. The legal term of fourteen days does not start until the day after delivery. In practice, you therefore often end up with at least seventeen days from the time of sending.

Not sure if the right time has arrived yet? We'd be happy to take a look with you and advise you on the best approach in your situation.

In 2026, judges take a strict line. Your 14-day letter must meet a number of strict requirements. If the letter is not correct, you run the risk of not being allowed to recover collection costs, even if the debt is otherwise clear.

Here are the five most important requirements:

• 1. The correct description of the 14-day period
  • Do not just name a fixed date, but describe the deadline as required by law.
  • The deadline begins the day after the letter is delivered to your customer.
  • For example, a safe wording is, "You have fourteen days to pay the outstanding amount, starting the day after this letter is delivered to you."
• 2. The exact amount of collection costs
  • You must name the specific amount of collection fees you will charge if payment is not made on time.
  • Merely stating that you will charge "collection fees" is not enough.
  • Use our collection fee calculator to determine the correct amount according to the legal graduated scale.
• 3. A clear VAT disclosure
  • Are you subject to VAT? Then you do not charge VAT on the collection costs. Your debtor only pays the graduated amount, for example € 40.
  • Are you exempt from VAT? Then you may increase the collection costs by 21 percent. If so, state this explicitly in your letter. For example, "The claim is increased by €48.40 (being €40 collection costs plus 21 percent VAT)."
• 4. Mention of collection register (Wki).
  • Based on the Quality Collection Services Act, you must be transparent about the party you hire.
  • Mention in the letter that if the debt is not paid, you will transfer it to a collection registry listed service provider, such as Credifin.
  • This fulfills your duty to inform and shows your client that you are taking the process seriously and professionally.
• 5. Proof of shipment and delivery
  • You must be able to make a plausible case that the letter was sent to the correct address.
  • E-mail is allowed, as long as you can prove that the message arrived at the correct e-mail address.
  • With mail, there is often a delivery fiction of two business days. If you send the letter on Monday, it is considered delivered on Wednesday and the deadline starts on Thursday.

Want to make sure your letter meets all the requirements? Then you can leave this entirely to us. We work with fixed, tested texts that are in line with the most recent case law.

Does your customer have several small invoices outstanding, for example monthly installments under about €267? Then the cumulation rule comes into play. Judges, since 2026, look more strictly at how you build up collection costs in these types of cases.

In practice, this is how it works:

• For the first missed term, you may charge the full minimum amount of €40.
• For subsequent missed installments within six months, a lower amount per installment is often considered appropriate, for example €20.
• If in your 14-day letter you default to €40 for each small invoice, a judge may find that unreasonable and reject your entire collection fee claim.

It is therefore important to apply the graduated scale and the cumulation rule carefully. We will help you create a reasonable and legally defensible cost structure per case, so that you will not face any surprises in possible proceedings.

Would you rather have the 14-day letter sent professionally? Then we will gladly take care of that for you. That way you can be sure that your letter is legally correct and complies with the 2026 rules.

• Loose WIK letter: €15 each (via Registered Mail™).
• From 10 WIK letters: €5 each (via Registered Mail™).

Do you have larger quantities or want to make fixed arrangements? Then together we will look at an appropriate rate for your organization.

Would you like all WIK letters to be sent by registered mail as well? If so, please contact us for additional costs and options.

The 14-day letter deadline has passed and your money is still not in your account. At this point, your patience stops and our work begins. As soon as the legal waiting period is over, you transfer the claim to us with one click. From then on, you no longer have to hope for payment; we enforce priority.

Once Credifin takes over the file, we activate immediately:

• Immediate pressure relief: We initiate the amicable collection process where the name of a certified collection agency provides immediate urgency.
• Legal Collection Costs & Interest: We claim full collection costs (according to the BIK scale) and legal interest on top of your principal. The debtor pays our efforts.
• Psychological superiority: Where your reminders were ignored, our multi-channel approach (mail, SMS and phone) does elicit a response.
• Real-time Control: In your online portal, you see live every action we take. No more uncertainty, but actual insight into progress.

Don't let your invoice linger any longer. Make that expired WIK deadline the starting point of your cash flow.